Problem, pics and hypothesis...what do you guys think?Overheating...powerhead gasket?

on_ice

Petty Officer 3rd Class
Joined
May 11, 2008
Messages
92
So, you can see in the link below that I have been having overheat issues:

http://forums.iboats.com/mercury-ma...es-pictures-story-videos-included-605656.html

In these pictures, you can see water and burnt oil/gas mixture escaping between the lower unit and the mid section. I believe this is another symptom of my overheating issue.

P1040234_zps6ab02f8f.jpg

P1040237_zps1af72df3.jpg


So the water/goo mixture seems to puddling up in the midsection and NOT exiting through the exhaust/propeller. It is being forced out as you can see. At first I thought there was an exhaust leak where the exhaust tube enters the lower unit. However, if this was true, something would have to be blocking the drainage in the lower unit, and causing it to go up. There is no such blockage and when the motor was together, it seemed like very little exhaust water coming from the propeller.


So I was trying to figure out where this stuff was coming from. When the motor was together, I remember water leaking from here(not my picture, stolen from internet):


225px-Merc_50_hp_zpsc0cfdae9.jpg


I started by first pressurizing the system with compressed air through the tell tale. I air easily flows through the engine out the water tube that connects to the waterpump housing. However, when I plug the water tube, I can hear air exiting somewhere near the same area as highlighted above. This could be because the exhaust assembly plate exits into the exhaust tube and isn't really sealed. I decided to test with water.

Here you can see I have the water tube exiting into a bucket, and the exhaust tube exiting into a plastic bag. As far as I know, these should be the only two exit points for water if I back flush through the tell tale.
P1040260_zps9e882d6f.jpg


When I backflushed with water through the tell tale, a steady stream came out the water tube but almost nothing through the exhaust. However, a lot of water came through from somewhere higher up in the midsection.

P1040263_zps7b12e636.jpg


So I am assuming whatever seals the power head to whatever it's attached to is leaking. Looking at the link below, I found a powerhead gasket( #8). Could it be this? What do you guys think?

http://www.**********/parts/search/...Up/Exhaust Plate and Shift Linkage/parts.html
 

on_ice

Petty Officer 3rd Class
Joined
May 11, 2008
Messages
92
Re: Problem, pics and hypothesis...what do you guys think?Overheating...powerhead gas

Well...the power head is off! What a grand ol time that was. No obvious cracks/holes and it's hard to tell by looking at the gasket. Maybe you guys will notice something.

One question, how does this come off?

P1040301_zpsd9590a28.jpg


More pictures:

P1040302_zpsbe6d33d2.jpg


P1040300_zps66a78c28.jpg


P1040298_zpsc8ce819f.jpg


P1040295_zpsa5088979.jpg


P1040294_zps933e200d.jpg
 
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